The present invention relates to improving the reliability of a manual control system for controlling the control rod of a nuclear reactor, and the method for replacing the same.
Heretofore, in a boiling water reactor, a system is proposed that applies a controller to a reactor manual control system and a rod position information system for controlling the hydraulic drive of the control rod, and realizes the desired functions through software processing. One example of the prior art system is the Advanced RMCS and RPIS (ICON, 71997th International Conference on Nuclear Engineering, Tokyo, Japan, Apr. 19-23, 1999). Further, Japanese Patent Laid-Open Publication No. 10-319171 discloses a surveillance function in a rod position monitoring system equipped with a rod controller and a position monitor controller that utilizes software processing.
In an existing boiling water reactor (BWR) plant, a hydraulic drive method is applied to drive the control rod. Therefore, a system in which a controller is applied for the reactor manual control system and the rod position information system so as to control the hydraulic drive of the control rod and to realize the functions through software processing is developed supposing that the system is to be applied to the existing plant. However, according to the prior art mentioned above, there is no actual consideration on how to introduce the system realizing the functions through software processing to the actual nuclear plant.
Moreover, the conventional system operating today performing hydraulic drive control of the control rod is composed of a special-purpose electronic circuit for realizing its function, or in other words, it is composed of hardware only. However, there is no sufficient consideration on how to rationally replace the conventional hardware with a rod control monitoring device that requires software processing.
Based on the problems of the prior art mentioned above, the object of the present invention is to provide a reactor manual control system that enables to easily replace the conventional system with the system realizing the necessary function through software processing. Another object of the invention is to provide a reactor control system that enables to control the control rod corresponding to the switching between automatic and manual control.
In order to achieve the above objects, the present invention suppresses the range of the duplex system when creating the software for controlling the reactor control rod, and further utilizes the conventional units that have interface with the machine system of the control rod driving device, which enables to partially replace the existing system with the new system.
The present system comprises an operation control means that processes (determines) the timing of the drive sequence at a duplicated data processing unit; a transmission control means that performs an AND logic within a predetermined period of time by receiving the duplicated data at another duplicated data processing unit and mutually transmitting data, and when said AND logic is fulfilled, selects one data and transmits said data; a transmission means that receives said data and performs protocol conversion so as to generate a serial transmission command and to transmit them serially to a plurality of transmission branch portions positioned downstream; and a control rod drive means that is branched from said branch portion and drives said control rod.
The serial transmission command is discriminated for each control rod including the synchronizing bit, the address of the control rod, and the excitation command for the solenoid valve, so the interface of the control rod drive means or control rod drive mechanism can be set similar to the prior art.
The rod position information system is also basically similar in structure. The position input system inputs the control rod position from the rod position detecting mechanism, and the position transmission means connected to each position input system via the branch portion transmits the position signal upstream, which is distributed through mutual transmission within the data processing unit. The position monitor system displays one of the control rod positions that had gone through software processing in the duplicated system. Here, the interface of the position detecting device or position detecting mechanism is similar to that of the conventional system.
Moreover, the reactor manual control system according to the present invention is characterized in that said rod control system is renewed with a control cabinet having a duplicated data processing unit of a microcomputer, and only the transmission system is further renewed that performs protocol conversion within the control cabinet of the control rod drive system. The control rod position monitor system is similar in that the cabinet of the control rod monitor device is renewed but only the position transmission system is renewed in the cabinet of the position input system.